1 PROJECT SUMMARY 2 3 The adoptive transfer of lymphocytes engineered to recognize tumor cells has shown tremendous promise in 4 patients with relapsed or refractory B cell malignancies. In this approach, patient derived T cells are programmed 5 in vitro with engineered T cell receptors (TCRs) or chimeric antigen receptors (CARs) that have affinity for cancer- 6 or lineage-specific antigens. Subsequent autologous reinfusion of the engineered T cells enables tumor targeting 7 and eradication. More recently, genome editing approaches have been proposed to improve engineered T cell 8 performance by knocking out genes that mediate graft-versus-host disease (for allogeneic transfer), that are 9 involved in tumor-mediated suppression of T cell efficacy, or that are recognized by potent clinically relevant 10 monoclonal antibodies. However, to this point no robust characterization of genome editing efficiency or 11 specificity has been performed in T cells. Much of my postdoctoral work has focused on developing methods to 12 characterize and improve the utility and genome-wide specificity of CRISPR-Cas nucleases, making me uniquely 13 suited to address this largely outstanding question. The primary aims of this proposal are therefore: 1) to 14 characterize and optimize the efficiency and specificity of genome editing in T cells, 2) utilize genome editing to 15 improve processes involved in T cell engineering, and 3) leverage CRISPR-Cas screens to enhance the overall 16 efficacy of engineered T cells. The proposed research will provide considerable insight into the feasibility of 17 implementing genome editing strategies in T cells as a means to improve tumor killing efficacy, persistence, or 18 manufacturing. Significant findings relevant to the fields of cancer immunotherapy, cancer biology, genome 19 editing, and gene therapy are expected. Areas of additional scientific training that will enable successful 20 completion of this proposal are knowledge of T cell biology and immunology, mentorship on in vivo cancer 21 modeling in mice, and experience implementing genome-wide CRISPR-Cas screens. The mentored phase of 22 the award will be supported by Dr. Keith Joung, a world-leader in genome editing technology development, and 23 by Dr. Marcela Maus, an expert in cancer immunotherapy. Dr. Joung, Dr. Maus, and nearly all other senior/key 24 personnel of this project are located at the Massachusetts General Hospital or in the greater Boston scientific 25 community. Professional and career development activities will include training in mentorship, responsible 26 conduct of research, grantsmanship, finance, and conflict of interest among other topics. National and 27 international meetings will continue to be attended to disseminate findings from the proposed research. The 28 academic and professional development environment at the Massachusetts General Hospital and Harvard 29 Medical School, combined with a top level mentorship team and scientific advisory committee, will offer the best 30 opportunity for further training as I transition to independence.